PATENT FOR THE MANUFACTURE OF EPSOM SALTS. 233 
conducted in the following manner : — 100 lbs. of muriate 
of ammonia are dissolved in 100 gallons of water, and the 
solution allowed to cool ; 70 lbs. of well-burnt lime are then 
slaked in water, and when cold stirred into a solution of 
muriate of ammonia in an earthenware vessel; mutual de- 
composition immediately takes place, and muriate of lime and 
caustic ammonia are formed in the liquid. This solution is 
transferred to a cylindrical vessel, lined with lead, and con- 
taining an agitator covered with lead ; carbonic acid gas is 
then forced into the solution by means of a force-pump con- 
nected with the bottom of the vessel, and the agitator is kept 
revolving until the solution is entirely decomposed, which 
may be known by the smell of ammonia no longer arising. 
The vessel will now contain a milky fluid, composed of car- 
bonate of lime and a solution of muriate of ammonia ; this 
fluid is removed, and allowed to settle ; the clear solu- 
tion of muriate of ammonia is then decanted off, and the 
precipitated chalk well-washed and dried. The solution of 
muriate of ammonia may be again used , . - . 
Tne moae ot carrying into effect the second improvement 
in the manufacture of carbonate of lime is as follows :— 100 
gallons of a solution of caustic ammonia, of 0.970 spec, grav., 
are introduced into a vessel similar to that last described, 
and capable of holding 120 gallons; carbonic acid gas is 
then forced in, and the solution becomes thereby converted 
into a solution of bicarbonate of ammonia, which is run into 
a cistern containing 100 gallons of a solution of caustic am- 
monia, of the same specific gravity ; and a solution of car- 
bonate of ammonia, of 1.050 spec, grav., is thus produced. 
This is mixed with a solution of muriate of lime, of 1.200 
spec, grav., in the proportion of 2 parts of the former to 1 
of the latter ; decomposition immediately takes place, and 
the whole becomes a gelatinous mass, which must be stirred 
until the carbonate of lime assumes the solid form. The mass 
is then allowed to subside, the clear solution of muriate of 
ammonia is drawn off, and the carbonate of lime is washed 
and dried. — Chem. Gaz. 
22 
